The University of Maryland's Center for Instructional Development and Evaluation has developed interactive video material for the Navy Medical Department to teach Navy medical corpsmen appropriate response procedures for each of seven emergency medical conditions: angina pectoris, acute myocardial infarction, congestive heart failure, stroke, diabetic coma, insulin shock, and epileptic seizure. An underlying philosophy of the design team and the subject matter expert was that the student could best master the process tasks by practicing them; the properties of computer-based interactive videodisc (CBIV) make it uniquely suited to implement this instructional principle. The videodisc simulation can include both patient attributes and environmental attributes that compare realistically with actual settings. A total of 15 emergency settings were developed to account for specific variations of the seven medical conditions; since the material is to be used for evaluative as well as instructional purposes, a second set of parallel lessons was developed for each setting, making a final total of 30 lessons in the system. Background information provided for the learner includes a glossary, reference lessons, and an introduction to the hardware and software. This paper briefly describes the system design and a representative lesson. (JB)